The present invention relates to the backrest of a chair in which a back-receiving portion is integrally molded with a frame.
In a conventional backrest of a chair, to the upper end of a metal back rod which extends from the lower portion of a seat upwards and rearwards, a back plate made of material different from that of the back rod is generally connected directly or indirectly via another material frame.
However, in the prior art, the back rod is made of material different from those of the frame and the back plate. Therefore, they are connected by screws, and there are disadvantages that it is impossible to shorten manufacturing processes and to decrease cost.
In view of the disadvantages in the prior art, it is an object of the present invention to provide the backrest of a chair in which a back plate is integrally molded with a frame which comprises at least part of a back rod, thereby shortening manufacturing processes, decreasing cost and providing comfort of a sitting person when one is reclined.
According to the present invention, there is provided the backrest of a chair, the backrest being an upright plate made of synthetic resin and comprising a low-rigidity flexible back-receiving portion for receiving the back of a sitting person, a pair of back rods, and pair of outer high-rigidity side frames each of which is spaced from said back-receiving portion via a slit, the lower end of each of said frames being connected to each of the back rods.
The backrest can be integrally formed from synthetic resin, thereby shortening manufacturing process and decreasing cost. The slits between the back-receiving portion and side frames provide sufficient flexibility and a comfortable chair.